Events were held around Wales on Thursday to mark the monarch's milestone birthday, including a 21-gun salute and fireworks at Cardiff Castle.
The Queen was in Windsor to light the first of more than 900 beacons in the UK and around the world.
Army Cadets lit the Snowdon one while others were lit in Swansea, Wrexham, Llantrisant and Cardiff Bay.
The 21-gun salute was sounded at 12:00 BST and there was a drinks reception for other people celebrating milestone birthdays and anniversaries.
"This is a wonderful opportunity for people to come together and commemorate their special milestones with that of Her Majesty," said Cardiff Lord Mayor, David Walker.
Meanwhile, 40 giant fibreglass models of the Queen's head are being displayed at a farm in Flintshire.
David Pickering won lottery funding to create them for the Diamond Jubilee in 2012.
He has decided to display them again on his land near Higher Kinnerton as the nation pays tribute to Britain's longest-serving monarch.

Omaree Lindsay, 19, of Cecil Road, Croydon, rode into Co-Op in Streatham Road, Mitcham, on 6 September.
He appeared at Croydon Magistrates' Court on Tuesday and pleaded guilty to a number of offences.
He was sentenced to 200 hours of unpaid work for offences including theft, failing to comply with a court order and driving a vehicle on the pavement.
District Judge Adrian Turned also ordered Lindsay to pay Â£150 in costs.
The court order Lindsay had failed to comply with was an order to complete unpaid for work in the community issued on 28 of August for a driving offence.

Highlights of all of Saturday's Scottish Cup ties will be on Sportscene on BBC One Scotland at 22:30 GMT.
And, on Sunday, Raith Rovers v Hearts (13:05) will be broadcast live on BBC One Scotland and Radio Scotland will provide commentary of that match and Albion Rovers v Celtic (15:00).
Sportscene returns with more highlights at 18:15 on BBC Two Scotland on Sunday, with a repeat at 23:40 on BBC One Scotland.
Scottish Cup
Aberdeen 4-0 Stranraer
Alloa Athletic 2-3 Dunfermline Athletic
Ayr United 0-0 Queen's Park
Bonnyrigg Rose 1-8 Hibernian
Dundee 0-2 St Mirren
Elgin City 1-2 Inverness CT
Greenock Morton 2-0 Falkirk
Kilmarnock 0-1 Hamilton Academical
Livingston 0-1 East Fife
Partick Thistle 4-0 Formartine United
Rangers 2-1 Motherwell
Ross County 6-2 Dundee United
St Johnstone 2-0 Stenhousemuir
Stirling Albion 2-2 Clyde
Scottish Championship
Dumbarton 1-2 Queen of the South
Raith Rovers v Hearts (13:05)
Albion Rovers v Celtic (15:00)

Police Scotland said it was informed about the find at 15:40 on Sunday.
The beach esplanade was expected to be closed "for some time" as a public safety precaution.
The road has been shut from the roundabout with the Beach Ballroom, the junction with Park Road and the junction with King Street.
A beacon has been lit at the top of Snowdon as part of festivities to celebrate the Queen's 90th birthday.
[NEXT_CONCEPT]
A teenager who used a "hoverboard" to enter a supermarket and steal a crate of Lucozade, has been spared jail.
[NEXT_CONCEPT]
Match reports of Saturday's Scottish Cup and Championship matches and previews of Sunday's Scottish Cup ties.
[NEXT_CONCEPT]
Roads have been closed around Aberdeen beach following the discovery of an ordnance device.