Drinking large quantities of water was a cure recommended by doctors in all the spa towns. For this treatment to be effective, time and gentle exercise came to be part of the cure and an essential part of the daily routine for guests. Grand colonnades were built, incorporating fountains and space for curists to promenade. Stone, and later cast iron and glass colonnades were built. Some are effectively covered walkways to shelter guests from the elements, and to protect the fine clothes of those who paraded also to be seen by others. Some colonnades even included shops.