There is a BA EC, one of the more grim ones on the network, but it is about the only place you can have a cig in an otherwise smoke-free airport. I don't remember anything about showers there though.

Otherwise it's a shared lounge called Le Anfore, a windowless place in the basement though probably more convenient for the departure gate. It does have showers.

Both lounges are open to F/J pax, Marco Polo Diamond, Gold and Silver members.