Haapsalu Communication Museum is a small specialist museum with an old-fashioned charm: switchboards, telephones, radio equipment, cables, and devices from the era when communication was physical, local, and often surprisingly beautiful. It is not a blockbuster, but it suits Haapsalu's slow pace.
The displays are best for travellers who enjoy practical history rather than polished spectacle. Allow a short visit, ask questions if staff are around, and pair it with the railway station or the old town. Together they give Haapsalu a pleasingly analogue character.