Visit the Kochi Fort which is also known as Fort Immanuel. It was built in 1503 by the Portuguese and later occupied by the Dutch. You can explore the surroundings, enjoy the sea breeze, and visit the Indo-Portuguese Museum which showcases the relevant history of the port city. Don't forget to take a break with some coffee and snacks at the cafeterias nearby.
Experience the serenity of Kerala with a cruise in the backwaters of Alleppey. You can even choose to stay overnight on a houseboat. You will see beautiful palm-lined canals, lagoons, and villages, and have the chance to buy fish and prawns fresh from the fishermen. Also, visit the Ambalappuzha Sree Krishna Temple, which dates back to the 17th century and is known for its unique payasam, a sweet dessert made with rice and milk.
Get wild at the Periyar National Park, where you can enjoy activities like bamboo rafting, boating, and trekking. The park is renowned for its elephants and tigers which live in the thickly forested environment alongside many other species of wildlife. You can also experience a guided tour of spice plantations or visit the Mangala Devi Temple. Bring along the binoculars, snap some pictures and take back memories for life.
If you have more time, visit the tea and spice plantations in Munnar or hike the trails to see the magnificent waterfalls at Athirapally. If you have less time, you could consider skipping the Alleppey Backwaters and opt for visiting the nearby hill stations like Thekkady or Kumarakom. Also, check the weather forecast before you go and pack accordingly. Don't forget to try the traditional Kerala food and take some souvenirs like spices and handicrafts.