Weather protection

I’ve noticed most doorways near to the sea (and some not so near) have barriers across the bottom. I’m told that sometimes huge waves can lash the streets and also huge downpours of rain.
Hard to believe but I don’t suppose people go to these lengths for nothing. Some places up here well above the sea also have them.

Lovely sunny day . Dodgy internet restricts me doing simple things like buying a diary for the year and having it sent to my next abode. I’m really lost without one!