London hotel with proper cot

[Dancingelkhound]

We're going to London for a few days and was just wondering if anyone had stayed in a hotel which offered a proper cot, as opposed to a travel cot?

DD won't sleep in a travel cot as she's too big, but is in a cot at home.

In previous hotels I've put a mattress on the floor for her surrounded by pillows, but a cot would be preferable so she can't get up and wander about.

Google isn't giving much help.