Pier 39

Public steps wired to play notes as you climb them. Free, outdoors, and kids will do the same eight stairs twenty times.

A mirrored maze on Pier 39 that takes about fifteen minutes to get lost in. Dim and disorienting, so it suits school-age kids more than toddlers.

Dozens of sea lions hauled out on the floating docks, barking and shoving each other off. Free, visible from the walkway, and most reliable in winter.

Small aquarium at the foot of Pier 39 where glass tunnels put sharks and rays overhead. About an hour, which is the right length for little kids, and the sea lions are outside afterwards.

A small play break in the middle of the busy waterfront, easy to pair with the carousel and a stop to watch the sea lions.

An observation wheel by the wharf with enclosed gondolas. Twelve minutes up top with the bay laid out, and no scary bits.