U.K. and Ireland - LHR layover for 12 hours

Hi guys

I've never been to the UK before, but have a layover at LHR for about 12 hours. So I was wondering what there is I can do?

How do I get into the city from LHR? Subway? Anything recommended? I figured I would go somewhere downtown for a few hours...

Thanks in advance

Take a look at some of the suggestions in the following threads to start:
http://www.flyertalk.com/forum/u-k-ireland/1327538-lhr-layover-what-do-london.html?highlight=layover+day
http://www.flyertalk.com/forum/u-k-ireland/1222851-8-hr-layover-lhr.html

12 hours is a nice block of time. By the time you clear customs, get into town you will have whittled away maybe 1-1.5 hours. Allow 2-2.5 to get back to the airport and clear security.

There is a lot you can do in that amount of time. I love the British Museum and the British Library. Fascinating places to spend time.

I would use the time to take one of the tour bus routes. Get to see the lay of the land, so to speak and often great fun.

Or for the British Museum:
http://www.britishmuseum.org/visiting/planning_your_visit/1_hour_at_the_museum.aspx

Take the Underground if you don't mind going a bit slower. Heathrow Connect is faster but more expensive and Paddington might not be a very convenient station for you. It really depends on your destination!

If the weather is fine I would go to St Jame's park or Regent's park and bring some food and just relax. Kew Gardens is also a good option but more expensive since you need to buy a ticket for entry.

If the weather is bad there are many museums to choose from. I completly agree about the British Museum, it is well worth a visit.

I completly agree about the British Museum, it is well worth a visit.It's also largely free - you only have to pay for special exhibitions - and very close to Russell Square station, around an hour on the Piccadilly Line from Heathrow.

I assume you're not a national of a country that requires a visa to enter the UK?

What I usually advise first time visitors to London is to go to either Waterloo or Embankment station and walk the Thames riverside walkway for a bit, then make your way past the Big Ben / Houses of Parliament towards the Royal Horse Parade, cross through the park and walk towards Buckingham Palace. That will give you a few highlights in a short period of time.

Second must-do would be to get to Tower Hill to see the Tower of London & Tower Bridge. All of this, plus a visit to the British Museum and a nice drink/chillaxing in Hyde Park on the way back to Heathrow can easily be done in your time frame.