Can anyone recommend a hotel that's right near to Terminal 3 at Heathrow? Doesn't have to be particularly fancy as we only need it for an overnighter before an early morning flight. There will be several adults but no transport so we'll need to be able to get to the terminal easily the next morning. I have looked at the Hilton Garden Inn which appears to be the only walkable hotel to the airport but it's pretty pricey!