Recommendations please: Europe/UK with 10-month baby (relaxed, walkable)

[user1234332]

I've been tearing my hair out trying to find the best spots for a holiday in May. Here are the criteria:
• 2 adults and a baby
• 1-2 weeks - happy to move spots halfway
• Reasonable transport links (no car)
• Somewhere interesting and with nice walks - everyone will get bored if we're parked in a hotel for a week

Ideally we'd want a hotel where we can eat in the restaurant in the evening (I think this will be easiest?), but isn't extortionately expensive. Or an apartment rental in a city, would that be more fun??

Destinations I've been considering: Sardinia, Rhodes, Scotland, Lake Garda...

Help!

Lake Garda is very doable with a pushchair, especially if you are based somewhere on the southeast shore. There’s a lovely flat walk connecting the little towns along that part. Public transport is pretty good too.

French Riviera could be good as you could base yourselves in Nice, or Antibes and there are trains running all along the coast so you could visit Cannes or Villefranche or Monaco. There are some nice beach clubs in Juan Les Pins where the beaches are sandy with shallow water.

Thanks both!