What this section covers. Parks, planetariums, zoos and interactive museums — and the planning rules that decide whether a day out works or collapses.
The three rules. One main activity a day, and no more: journeys eat more time than you allow for. Group by area — Chapultepec one day, Coyoacán and the south another, Xochimilco another — and never cross the city twice in a day. And respect the altitude: at 2,240 metres, the first two days are slower, with water, a cap and sunscreen, because the sun is strong even when the air is cool.
The reliable days out. Chapultepec fills one entirely: a free zoo, a lake with pedal boats, the castle on the hill and the Papalote Museo del Niño, built for children to touch everything. Xochimilco by trajinera, hired by the boat and by the hour. The Planetario Luis Enrique Erro, refitted with a Digistar projector and reclining seats. The Museo del Juguete Antiguo, four floors of obsessive collecting. And KidZania, where children run a miniature city.
Practical notes. Under-fives travel free on public transport. Avoid the Metro with a pushchair at peak hours (07:00–09:00 and 18:00–20:00) — a baby carrier works better than a large pushchair in the historic centre, where pavements are narrow and uneven. Most museums close on Mondays and charge little or nothing for children.