Weekend trip recommendations

Hi, me and my friend (both 18yr old females) are planning on taking a weekend trip or around 4 days somewhere in Europe (end of August). We’re both pretty well travelled so we know the ins/outs but would still like a safe location. We were looking at Georgia but decided that’s not an option for 2 young girls so we were wondering if you guys had any ideas?

We would be flying from London! We would also like somewhere that’s close by (we were told St Petersburg and whilst I wouldn’t be opposed to that for a long trip, I’m not keen on flying 8 hours with a layover for 2 days…)

We don’t necessarily have a budget but not 5 star, Michelin restaurants, etc

We’re also looking for somewhere that’s maybe a bit more nature/architecture than going out? Neither of us are into clubbing only bars so places like Ibiza aren’t preferable

We were thinking things like Stockholm, Budapest, Venice etc

It would be great to hear the ups and downs for different places.

Thanks!