If you're visiting London with kids, we would like to suggest the Park Plaza Westminster Bridge hotel. Why do we and our clients like this hotel?
It is modern, new, not overly expensive, and most importantly, it is centrally located. There are so many great tourist attractions within walking distance: London Eye, Parliament, Big Ben, Victoria Tower, and many others.
The staff are professional, courteous and well trained. The rooms are a very good size, as is the well equipped and supplied bathroom, with a bath and a separate shower. The beds are very comfortable.
There is a spa and pool but we did not make use of it on this trip.
You can take external facing rooms, so you might look at the London Eye or Big Ben.