In the morning, visit Robber's Cave, a cave formed in the Himalayas with a small river flowing inside. Afternoon, explore the Forest Research Institute, a research institute located in a lush green campus, which has six museums showcasing the flora and fauna of Uttarakhand. In the evening, take a stroll at the famous Paltan Bazaar and shop for unique souvenirs.
In the morning, take a cable car ride at Gun Hill, which provides a panoramic view of the Himalayan ranges. Afternoon, visit Kempty Falls, a beautiful waterfall that cascades down from a height of 40 feet. In the evening, explore the famous Lal Tibba, the highest point in Mussoorie, known for its scenic views of the surrounding hills.
In the morning, drive to Gaurikund and start your trek to Kedarnath, a holy Hindu shrine located at an altitude of 11,755 feet. The trek is scenic and moderately difficult, passing through picturesque villages and lush green valleys. Afternoon, visit Kedarnath Temple, one of the twelve Jyotirlingas, dedicated to Lord Shiva. In the evening, attend the evening aarti at the temple, which is a divine experience.
While in Dehradun, you should consider visiting the Mindrolling Monastery, a Buddhist monastery that houses the world's largest stupa. Another side trip could be to Haridwar, a holy city located on the banks of the river Ganges. To maximize your fun, you can try local delicacies like Kumaoni cuisine and shop for handicrafts and woolen items at the local markets. Additionally, you can consider hiring a local guide for an immersive experience.