What is the importance of 'Rani ki Vav' featured on new ₹100 note?

The archaeological site 'Rani ki Vav' that features on the rear of new ₹100 notes is a UNESCO World Heritage Site in Gujarat's Patan. The 11th-century site is a stepwell which was built by the Solanki dynasty's queen Udayamati as a memorial for her deceased husband Bhimdev. In 2016, it was awarded the 'cleanest iconic place' in India title.