1) The concept of virtual reality (VR) involves creating a simulated environment that can be explored and interacted with using specialized headsets and input devices.

2) The Taj Mahal, located in Agra, India, is an iconic mausoleum recognized as a UNESCO World Heritage site. It was built in the 17th century by Emperor Shah Jahan as a testament to his love for his wife and stands as a masterpiece of Mughal architecture and a symbol of India's cultural heritage.

3) As of 2023, the COVID-19 pandemic continues to impact countries worldwide, with efforts focused on vaccination campaigns, public health measures, and economic recovery.

4) The musical "Hamilton" has won numerous awards, including 11 Tony Awards and the Pulitzer Prize for Drama.