We are thinking of going to Lisbon for the day with our 3 children, age between 7 and 12. Bearing in mind the limited time that we'll have there, can anyone suggest a couple of must do things. Thanks.

I would recommend the Castelo de Sao Jorge which is perched above the city and has great views from the terraces of the city and the river Tejo. The trip up to the Moorish castle runs through some interesting neighbourhoods with narrow, winding streets and gives a real sense of the old city. The castle grounds can be wandered through and there's gift shops, cafes etc to have lunch.

The Jeronimo monastary and the navigator monument are both worth looking at. Or drive around and see the football grounds!

IF you like shopping the Colombo shopping centre is great, get metro to Oriente and there it is.
Our favourite was the aquarium and just walking about.
Its really easy to get aroud as its not too spread out.
The castle is nice also but take a tram I think number 28 so the kids dont moan about walking up the hill. You get a lovely view of Lisbon from there.
Loads of nice interesting places to eat in the Alfama if your kids are adventurous and would try an authentic old style eatery that looks like someones front room!
Its a pity you only have a day as 2 would be better.

Agree with all of the above:
Jeronimos Monastery
Castle of St George (great views)
Theres also the Tower of Belem along the riverbank..like a miniature Tower of London..from the top you can see across the vast river Tejus and also see the high figure of Christ the Redeemer.
Theres a nice line up of cafes/restaurants along a pretty marina..I remember my friend and I stopped at one of these for lunch.
The views along the river are quite breath taking.

Hope you & family have a lovely day

Thanks for the replies, I'll let you know how we get on.