Hi Friends,

I am traveling to Nepal Via London , I have a 12hr transit , i was thinking to utilize time and see london.

Me and my wife has green card and my kid has a US passport.  Do we need to take visa for get out of London airport.  If where where can i get transit visitor's visa, and how much does it cost. Anyone  has similar experience please share

Yes,
You and your wife do need visa though ur child does not. The visa is not guaranteed. I have frens who got approved and rejected for 24 hr transit visa to London. They all had gc. Abt the cost , I forgot but shud be less than $100.

 Few years ago i had a 12 hour transit in London. I went to the immigration and told them i can't stay inside airport for more than 12 hours and i want to go out and sleep in a Hotel.

The immigration officer asked me couple questions like : what i do in US and blah blah and the lady asked me: Do you need 12 hours or 24 hours Visa ? i said 12 hours should be enough. 

That's all ......

She stamped for 12 hours temporary permit in my passport. I don't think i paid any money.

I was in a F1 visa that time.