Lisbon
Tiled hills, cheap seafood, and the best sunset spots in Western Europe. Stay 3–5 days, or 5–7 with sintra and the coast.
Long days, open terraces, warm seas in the Mediterranean, and the last month before peak pricing hits.
The best month for Mediterranean coast and islands if you want swimmable water without August. Ferries are on full schedules by late May.
A beach, a mountain and Gaudí, all reachable on foot from a single apartment. Stay 4–5 days.