Borough museums: Excluding the City, London has 32 boroughs. Some of these have their own museum devoted to telling the story of the borough's local history, and some don't. By my calculations about 40% don't, which is an unexpectedly high proprtion given that the average London borough has a population the same size as Newcastle, Brighton, Derby or Hull. Or it's an unexpectedly low number given that cash-strapped councils are being forced to make savings, and culture's an easy non-essential to cut.
Here's an updated version of a list I first attempted ten years ago.
★☆☆ Croydon:Museum of Croydon[Croydon CR9 1ET closed Sun, Mon] (free)
Mildly interactive black vault at Croydon Clocktower, which I've never quite enjoyed. [review 2009]
★☆☆ Enfield:Museum of Enfield[Enfield EN2 6DS] (free)
Unwelcoming rump tucked away inside the Dugdale Centre. (FortyHall is much better)
★☆☆ Greenwich:Greenwich Heritage Centre[Woolwich SE18 4DX, closed Sun, Mon] (free)
Well concealed maze of ageing historical displays at the back of Artillery Square ('temporarily' closing in mid-July)
★★★ Hackney:Hackney Museum[Hackney E8 1GQ, closed Sun, Mon] (free)
Large ground floor gallery at whatever the library's called these days, with an immigration focus.
★★★ Harrow:Headstone Manor Museum[Headstone HA2 6PX, closed Monday] (free)
14C manor house, beautifully restored, just reopened, and my top recommendation if you've never been. [review 2018]
★★☆ Havering:Havering Museum[Romford RM1 1JU, closed Sun, Mon, Tue] (£3)
Volunteer-led displays within part of the ground floor of the former Romford Brewery. [review 2011]
☆☆☆ Hillingdon: No borough museum
★★☆ Islington:Islington MuseumFinsbury EC1V 4NB closed Wed, Sun] (free)]
Modern basement under Finsbury Library, with an artefact-led community focus.
☆☆☆ Lambeth: No borough museum
☆☆☆ Lewisham: No borough museum
☆☆☆ Merton: No borough museum
☆☆☆ Newham: No borough museum
★★☆ Redbridge:Redbridge Museum [Ilford IG1 1EA closed Sun, Mon] (free)
Windowless millennial circuit within Ilford Central Library, plus temporary exhibition space. [review 2008]
★★★ Richmond:Museum of Richmond[Richmond TW9 1TP, closed Sun, Mon] (free)
Top class historical repository on the second floor of the Old Town Hall.
☆☆☆ Southwark: No borough museum (ever since the Cuming Museum burnt down)
★★★ Sutton:Honeywood Museum[Carshalton SM5 3NX, closed Mon, Tue] (free)
Restored and reopened in 2012, opposite Carshalton Ponds, with a lovely friendly atmosphere. [review 2012]
☆☆☆ Tower Hamlets: No borough museum
★★★ Waltham Forest:Vestry House Museum[Walthamstow E17 9NH closed Mon, Tue] (free)
Former workhouse, with a focus on transport and the domestic, plus a rather nice small garden.
☆☆☆ Wandsworth: No borough museum (closed 2007)
☆☆☆ Westminster: No borough museum