Start your day with a visit to the Brihadeeswarar Temple, an architectural marvel built in the 11th century by the Chola dynasty. The temple complex houses several smaller temples and shrines and is a UNESCO World Heritage site. Marvel at the towering 13-story vimana, which is topped by a massive stone kalash.
Next, head to the Thanjavur Royal Palace and Art Gallery, which was once the residence of the Nayak and Maratha rulers. The palace complex houses a museum that displays a collection of art and artifacts from the Chola and Nayak periods, along with a small library with rare manuscripts and books.
After the palace, visit the Saraswathi Mahal Library, located inside the palace complex. It is one of the oldest libraries in Asia and houses over 60,000 rare manuscripts, including palm leaf manuscripts, paper manuscripts, and books in Indian and European languages.
For lunch, head to Sathars, a popular restaurant known for its Chettinad cuisine. Try the spicy curries and the biryani, which are local favorites.
Visit the Schwartz Church, which was built by the Danish missionary Christian Friedrich Schwartz in the 18th century. The church is known for its beautiful stained glass windows and the marble tablet that commemorates Schwartz's work in the region.
End your day at the Tamil University Museum, which is located on the campus of the Tamil University. The museum houses a collection of artifacts and exhibits related to the Tamil language, literature, and culture.
There are several other places worth visiting in Tanjore, including the Gangaikonda Cholapuram Temple, the Alangudi Guru Temple, and the Punnainallur Mariamman Temple. If you have more time, you could also consider visiting the nearby town of Kumbakonam, which is known for its temples and cultural heritage.