Was in the Netherlands a couple of years ago and found a coed sauna. I had to ask around because gay saunas are popular there and they are not my style. When I arrived, they directed me to the men's dressing room where I disrobed completely. Through the door on the other side of the dressing room was the spa area. They had two saunas a differing temps, a steam room, a jacuzzi, a large lap pool, and a cold water dunking pool. They also had a patio which lead to a sunning area and two other saunas (one with hot rocks and another wood burning).
The thing that surprised me was the number of young groups of women who were there together. I realized like American women might do spa treatments or have their hair done together, Dutch women sauna. I was also surprised that people didn't wrap their towels around them, but only sat on them. Everyone was fully exposed. Finally I was surprised how many people were there the day I went. In one of the saunas, it became so crowded that my legs were touching the women on either side of me and my knees were touching the woman in front of me.
Being squished together with so many nude women scared me a bit as I thought I might get erect. However the heat was so intense, all I could concentrate on was keeping my hair from not burning off. ;-)