Where to stay in Lisbon

[littlequestion]

We're going to Lisbon in the summer for three nights with our two teenagers. Can anyone recommend somewhere to stay? I have no idea of areas but would like to be fairly central. Thinking of self-catering rather than a hotel to keep costs down. TIA.

I went with friends in December 2018 and we stayed for 4 nights in Chiado area in the old city and we had a fab 3 bedroom apartment! Location was AMAZING. Loved Lisbon and would def go again and stay in that area again too.