Day trip ideas please?

[SmiledWithTheRisingSun]

I have decided to go on a spur of the moment day trip with DH & DC.
We are in London - where would you suggest we go?

Kensington, museum's, high street, the palace, the park.

Battersea, the park and cats and dogs.

Childhood museum at Bethnal green have activities.

South bank, walk along the river have a drink somewhere.

Greenwich

Depends what you like doing

Goethe train to Brighton
Kew Gardens
Hampton Court

Tate modern art gallery its free