100 London Road, Forest Hill, London
This museum has both permanent museum-style exhibits (musical instruments from all around the world, as well as stuffed animals/birds in glass cabinets) combined with temporary exhibitions, children's workshops and a small but perfectly stocked aquarium (think finding Nemo), with glass viewing panels at toddler level. There's a good cafe/restaurant with highchairs which extends into a large Victorian glasshouse and the shop has a good selection of museum related toys and crafts. Gardens also extend around the South side of the museum, where you'll find nature trails and places to picnic. Open 10.30am-5.30pm daily, (Closed Dec 24-26). Admission free (except temporary exhibitions).
We strongly recommend you ring Horniman Museum and Gardens before you set off on your family day out, to make sure they are open and to confirm admission prices. It may also be worth visiting the website for Horniman Museum and Gardens, www.horniman.ac.uk, to see if there are any special events on the day for which you may have to book a ticket. Please also be aware that if Horniman Museum and Gardens hosts birthday parties, this may limit the access in the cafe/restaurant areas.