Greenwich vs Antibes

Greenwich is lovely, feels like a little seaside town somehow, get some food at the market or fish and chips, and if time walk up to the Royal Observatory, a beautiful building and home of Greenwich Mean Time, stand on the prime meridian, and enjoy amazing views across London from the hill.

Greenwich, great for a longer afternoon wandering the market, park, historic streets and riverside without needing a strict itinerary.

I would also strongly recommend you select an apartment that has a good kitchen and dining table. ... I think a day at Greenwich would appeal to the teens

Greenwich is a good trip.

Greenwich, loads to see here, including Greenwich Park, Old Royal Naval College (free areas), and a market with various food stalls.

I loved Antibes though and was happy with our choice to make it our base for about a week.

While the Côte d’Azur is horrible in my opinion, I find some small towns like Menton and Antibes very charming.

Nice, Cannes and Antibes have all been great places to spent a few days. Beautiful weather, sea and food & bars. You should go.

Eze, Monaco, Cannes and many more places (like Menton, Antibes and even Italy) are quickly and easily reachable by train from Nice.

5 nights in Antibes is not too long at all in this context. It gives you proper downtime plus flexibility for easy day trips like Nice, Cannes, or even just slow beach days.