Task: Question Generation
Input (English): The literal meaning of Durbar Square is a "place of palaces". There are three preserved Durbar Squares in Kathmandu valley and one unpreserved in Kirtipur. The Durbar Square of Kathmandu is located in the old city and has heritage buildings representing four kingdoms (Kantipur, Lalitpur, Bhaktapur, Kirtipur); the earliest is the Licchavi dynasty. The complex has 50 temples and is distributed in two quadrangles of the Durbar Square. The outer quadrangle has the Kasthamandap, Kumari Ghar, and Shiva-Parvati Temple; the inner quadrangle has the Hanuman Dhoka palace. The squares were severely damaged in the April 2015 Nepal earthquake.
Output (English): When did a notable earthquake occur that damaged Kathmandu's Durbar Square?