At Inthakhin, inside the Wat Chedi Luang grounds in Chiang Mai, there was a sign notifying people that women were NOT allowed inside the Wat because…they menstruate. Apparently, one of the pillars of the city was enshrined inside, and if a menstruating woman entered, it would create widespread social unrest.
Because men are the ones keeping the world from spiralling out of control or something.
We adhered to the local custom, but I took the above picture to show Alice what was inside. I will say, it was pretty beautiful. The Thais do detail REALLY well, and they keep their Wats in good repair.