Recently I went to Pushkar. I visited a temple of Lord Kartikeya where women aren't allowed.
What is the reason behind this?
When Lord Kartikeya was doing meditation Lord Indra gets jealous that Brahma might give him more power than himself. So he plans to distract Lord Kartikeya by sending the most beautiful Apsaras. Lord Kartikeya gets angry and curses that "any woman who comes to his place to distract him from his meditation shall turn into stone".
In time, it has become a belief that women coming to visit Pushkar might get cursed instead of being blessed. That's why women are not allowed in Pushkar.
I think it could be because of the same reference story as in case of Lord Kartikeya's Kurukshetra temple. It was about a competition between Lord Kartikeya and his brother Lord Ganesha and its after effects. I have already discussed about this in my question here.