Spaces with unusual acoustics, long reverb, echo's etc.

["riluttante" riluttante]

Hi everyone,

I'd love to hear some of your recommendations/rumors about locations with u=
nusual
acoustics, long reverb, echo's etc.
Doesn't matter where they are.

Does anyone know which space has the longest reverb in the world?

Does anyone know of places with unusual, directional echo's such as large m=
arble domes etc?

I'm particularly interested in spaces where the sound changes dramatically =
depending on the
listener's position in the room, such as domes with a strong "focal point" =
type echo in certain
spots.
This is a fascination of mine, and I'm hoping to be able to visit some inte=
resting sites...

Sources/forums for further information about this topic would also be highl=
y appreciated.

Thanks very much for any suggestions!
Alex