Which armoured cruiser survives as a museum ship?

Are any armoured cruisers preserved today?

Yes; Greece's Georgios Averof survives as a floating museum and ceremonially active ship, while USS Olympia is a protected cruiser rather than an armoured cruiser.

Georgios Averof is the clearest preserved armoured cruiser discussed here. The Greek ship belongs to the wider Pisa design family and survives as a floating museum. USS Olympia is also preserved, but it is a protected cruiser rather than an armoured cruiser. Averof remains crewed and carries active-service ceremonial status, giving the preservation story unusual continuity.