Water cities

I've never been to Venice, but I think the same question would apply to what I've observed in Amsterdam and Brugge. How is it that houses are built on the water so long ago and they're still standing? From what I understand, water is not so good for a foundation. I read that the houses in Venice are on wooden piles, but it seems like the joints and some of the bricks are submerged, too. Was the area more drained at the time or did construction happen in scuba gear? What's maintenance like? If anyone just wants to send me a link to a concise history or a diagram or something, that would be awesome!

Water cities

I've never been to Venice, but I think the same question would apply to what I've observed in Amsterdam and Brugge. How is it that houses are built on the water so long ago and they're still standing? From what I understand, water is not so good for a foundation. I read that the houses in Venice are on wooden piles, but it seems like the joints and some of the bricks are submerged, too. Was the area more drained at the time or did construction happen in scuba gear? What's maintenance like? If anyone just wants to send me a link to a concise history or a diagram or something, that would be awesome!