The Emperor Was pleased with Tulsidas and presented the Hanuman temple by having an Islamic crescent Moon finial which adorns the temple spire. It's also claimed that due to crescent moon symbol on the spire, the temple wasn't ruined through the Muslim rulers who invaded India at many times. This https://hanumanmandirwellington.org.nz/why-is-hanuman-mandir-wellington-popular-among-devotees/