Wales Election 2016: 11 key battlegrounds

The polls will open for the assembly election on Thursday - and it will be some time before the first results of the night are declared.

But like any election, while some seats are considered safe for the party defending them, others may be more likely to change hands.

Here, BBC Wales lists 11 assembly seats where there is a threat to the party that is defending it - either on the basis of previous assembly results, or what happened at the UK general election.

Keep an eye on these contests - not all 11 will switch, but how the parties do in them will be a good indication of the kind of night they are having.

Aberconwy - held by the Conservatives

Conwy Castle

Why is this seat interesting? Aberconwy is held by the Tories' Janet Finch Saunders but is a three way marginal which was Plaid Cymru's between 2007 and 2011. Plaid in 2011 came 1,567 votes short of winning, with Labour only around 110 votes behind them.

If Plaid has a decent night at the polls, this could be a seat the party wins back.

But, given Guto Bebb won the Westminster seat here in 2015 with a majority of 3,999, if the Tories have a good night in north Wales it could be a difficult task for Plaid.

It is also not totally outlandish to think Labour could leapfrog Plaid and snatch the seat, based on 2011 figures.

Estimated declaration time: 03:00 BST

Find out who is standing and the results here.

Brecon and Radnorshire - held by the Welsh Liberal Democrats

Bethel Square, Brecon

Why is this seat interesting? Losing Brecon and Radnorshire would be a big psychological blow for the Welsh Liberal Democrats, leaving the party without leader Kirsty Williams.

Ms Williams' party has a fight on its hands to defend the seat, which she held with a majority of 2,757 in 2011, after the Tories' Chris Davies beat former Lib Dem MP Roger Williams by 5,000 votes last year.

If she can defend it, the result may show the Welsh party still has a future in its Powys heartland.

If the Tories fail to win, questions may be raised over whether the publicity over the controversial selection of Tory challenger Gary Price damaged his party's chances.

Estimated declaration time: 03:00 BST

Find out who is standing and the results here.

Cardiff Central - held by Labour

The Cardiff Central constituency includes the busy shopping areas around Wellfield Road

Why is this seat interesting? On paper Cardiff Central is the assembly's most marginal seat.

In 2011, the Liberal Democrats lost by just 38 votes to Labour.

Despite the maths, it has since become assumed knowledge that this is safe territory for the incumbent candidate Jenny Rathbone, especially given the 2015 result where the party's Jo Stevens won with a majority of 4,981.

But that has not stopped the Liberal Democrats from bombarding the area with literature in a bid to win Cardiff Central again - something that would be a massive confidence boost for the Lib Dems.

The Lib Dems' Eluned Parrott, who is also standing on the South Wales Central list, is challenging Labour's Jenny Rathbone here.

Estimated declaration time: 05:00 BST

Find out who is standing and the results here.

Cardiff North - held by Labour

Cardiff North encompasses the capital's northern suburbs, including Whitchurch

Why is this seat interesting? Cardiff North is one of several Labour-Tory fights in south and north east Wales which will be watched closely to see if the Conservatives can repeat last year's UK general election successes.

Labour's hopes to win back Cardiff North at Westminster were dashed when new Conservative candidate Craig Williams boosted his party's majority from 194 to 2,137.

Julie Morgan, the area's former Labour MP, is defending the assembly constituency against Rhiwbina Tory councillor Jayne Cowan. Both are well-known locally.

Estimated declaration time: 05:00 BST

Find out who is standing and the results here.

Delyn - held by Labour

Flint Castle

Why is this seat interesting? Delyn will be a test of whether the Conservatives can translate last year's Westminster win in neighbouring Vale of Clwyd into a wider set of victories, and whether adverse publicity on public services in north Wales will hurt Labour at the ballot box.

The Tories' are targeting it together with a group of other North Wales seats, and are hoping they can overturn Labour's assembly majority of 2,881.

This Labour-held seat is being defended by a new candidate, Hannah Blythyn. She faces Tory challenger Huw Williams.

Estimated declaration time: 02:30 BST

Find out who is standing and the results here.

Gower - held by Labour

Gower includes stunning beaches, including the three-mile stretch of Rhossili Bay

Why is this seat interesting? Despite its marginal status, the Conservatives' May 2015 win in Gower was a shock to many.

The constituency had been held at Westminster by Labour for more than a century, but the Tories snatched it by a margin of just 27 votes.

After the election, there were suggestions that Labour only realised it might lose Gower to the Tories the night before it happened.

The question will be whether Labour has done enough to get the party's vote out this time around, and stop history repeating itself.

Labour's candidate is deputy farming minster Rebecca Evans, who has moved to the seat from the Mid and West Wales regional list seat, after Edwina Hart decided to stand down. She defends an assembly majority of 4,864. She faces Conservative candidate Lyndon Jones.

Estimated declaration time: 03:00 BST

Find out who is standing and the results here.

Llanelli - held by Labour

Llanelli Town Centre

Why is this seat interesting? In the seats where Plaid Cymru could feasibly beat Labour, Llanelli is the tightest contest.

In the 2011 election, Plaid Cymru's Helen Mary Jones was beaten by Labour's Keith Davies by just 80 votes.

Ms Jones is standing for Plaid again, but this time Institute of Welsh Affairs director Lee Waters is fighting for Labour.

If Plaid win, it will mark the return to the Senedd of one of the party's most senior figures. If Labour win, the party will get an AM who has been highly critical of the Welsh Government in the past, and has promised not to be a "nodding dog".

You can read more about Llanelli in our seat profile.

Estimated declaration time: 02:30 BST

Find out who is standing and the results here.

Rhondda - held by Labour

Rhondda Heritage Park

Why is this seat interesting? Plaid Cymru leader Leanne Wood is defending her place on the South Wales Central list, but she is also hoping to unseat public services minister Leighton Andrews.

And it is a tough battle for Ms Wood. She faces the task of overturning Mr Andrews' majority of 6,739.

Winning Rhondda would be a coup for Plaid Cymru, giving the party a foothold beyond the party's heartlands, while also depriving the Labour assembly group of a senior figure.

Plaid held Rhondda between 1999 and 2003 in the first term of the assembly. But is the scale of the challenge too much in 2016?

Estimated declaration time: 05:00 BST

Find out who is standing and the results here.

Vale of Clwyd - held by Labour

Rhyl

Why is this seat interesting? Like the Gower, the Vale of Clwyd is another Tory win from the general election that the party will be hoping to replicate.

And like Gower, it was won on a knife-edge with a margin of 237 votes.

Labour's Ann Jones is defending the seat she has held since the inception of the assembly, and a majority of 4,011. She faces the Conservatives' Sam Rowlands.

Local issues have played a major part in the north Wales campaign, especially those surrounding Betsi Cadwaladr University Health Board.

The area's Ysbyty Glan Clwyd has been the subject of a number of negative headlines - it remains to be seen whether voters will treat the election as a referendum on the performance of public services.

Estimated declaration time: 02:30 BST

Find out who is standing and the results here.

Vale of Glamorgan - held by Labour

Vale of Glamorgan constituency includes the coastal resort of Barry Island

Why is this seat interesting? Vale of Glamorgan is another Labour-Tory marginal that the Conservatives hold at Westminster level and would like to win at the assembly too.

If they pull it off, the Conservatives would rob Labour of a senior Welsh Government minister - Jane Hutt who holds the finance portfolio.

Ms Hutt is defending a majority of 3,775, and faces Conservative challenger Ross England.

Estimated declaration time: 05:00 BST

Find out who is standing and the results here.

Wrexham - held by Labour

St Giles' Church, Wrexham

Why is this seat interesting? Wrexham is one of several Conservative targets in north east Wales and another potential ministerial scalp for the party.

Lesley Griffiths, communities and tackling poverty minister, held on to Wrexham at the last election with a majority of 3,337.

But it is the UK general election result that has made this seat interesting.

Labour kept Wrexham, but with a reduced majority of 1,831 with the Tories coming second.

The Conservatives have never held Wrexham at any level. Will UK Tories woes prevent a shock result, or could this red through-and-through seat turn blue?

Estimated declaration time: 03:00 BST

Find out who is standing and the results here.