What to do with my 10-hour layover at Heathrow?

This has been covered many times, do a search.

If your flight is booked through, i.e. not two separately booked flights, you can check your luggage through.

Basically you have loads of time to get in to London on the tube and do all kinds of things.

You can't see Big Ben without applying to a UK MP several months in advance as it's not open to the public but you can see Queen Elizabeth tower inside which it's held if you like.

As for a decent boozer, try the porterhouse on Maiden Lane. Take a tube to Covent Garden.

#1 is right search TT for Heathrow layover and see what you get..

However, it is a nice day in Dublin and I'm in a helpful mood.

Allow two hours on a good day from getting off the plane and getting to central London. Buy a Zone 6 travelcard at LHR tube station and get the tube. Go to Westminster station on the District Line, you can change at somewhere like Hammersmith to do this. This puts you in front of the Houses of Parliament ('Big Ben' or QE tower as it is really known as Fwoggie sez, used to be St Stephen's Tower), Westminster Abbey and Westminster Bridge all of which are great photo opportunities.

You are not really going to find a true 'English pub' in tourist central, they know their markets here and it is all a little bit or a real lot faux. However, The Red Lion in Whitehall (towards Trafalgar Square) might not be a bad choice. It is used by pollies and their minions so has some non-touristy aspect to it.

You have fish and chip choices at various places along Whitehall if it is lunchtime by then (including The Red Lion) such as Silver Cross (which does some great ales) right up near Traf Sq. Not cheap, not great food but these are options.

This puts you at Traf Square. More photo ops, feel free to dive into the National Gallery for a bit. You have, based on time, two choices I reckon. One, go up the Mall to Buckingham Palace and then across Green Park to Picadilly tube and back to LHR or two, go to Leicester Square Square and Picadilly Circus (and then again onto the Picadilly line) for more photo ops.

You are probably going to need to allow 2.5-3 hrs to get back from central London to LHR and checking in time and so on but that depends on the requirements of your airline, checked through baggage and so on.

Get an all zones day travel card. I think it's about £8. That will allow you get on and off as many trains as you like and many red buses too. It lets you to see a big chunk of Greater London in a very short space of time.

I disagree with the use of public transport, yes cheaper and a bit more flexible but you don't get history or if on a bus, you don't know when the next stop is coming up.

As a tourist I would suggest one of the Big Bus Companies, yes they are more expensive but they cover the main things a tourist is looking for. They also tell you a lot about London and the particular thing you are looking at, as in why Big Ben is called such. Google Big Bus Company or The Original ?????? (sorry can't remember its full name) to check out prices and routes.

As to luggage, depending on your booking it is more than likely checked thru to your final destination, so shouldn't be a problem.

as to getting in and out of London/Heathrow.

take the tube which will be approximately 1 hour or take the Heathrow Express which is roughly 20 minutes to Paddington. A Big Bus stop is about a block away from the station, lots of eateries around not sure any would come up to your expectation of a London Pub though.

be aware that the Heathrow express costs a FORTUNE. Get that one-day £8 travelcard, get the tube in and out, and then you can hop on buses/tubes as much as you like.

the centre of London is relatively small and walkable. I'd get out at Leicester Square (same line from Heathrow) and then consult the maps in the ticket hall to see which way you want to go. You can pick up some local maps there too. This puts you under 10 mins walk from Trafalgar Square, the Mall, Covent Garden, ,the Thames, London Eye, lots of other quintessential London stuff.

the area is always busy. Watch your bag and if you want to stop to consult a map, don't stand in the middle of the pavement getting in the way. :-)

you can take a Taxi for a 20-30 minute ride to Windsor, have a look at Windsor Castle, and take a walk along the River, or cross the River into Eaton for a look at the College, and a mooch around Eaton town which is quite attractive.

You only live once - don't stay in the airport. Do go back early though.