Sure, I'd be happy to help you plan your one-day itinerary in Kodaikanal!

Day 1:

• Start your day with a visit to the Kodaikanal Lake, which is a beautiful man-made lake surrounded by lush greenery. You can take a boat ride or simply walk around the lake and enjoy the serene atmosphere.
• Next, head to the Coaker's Walk, which is a scenic walking trail that offers stunning views of the surrounding hills and valleys. You can also visit the Telescope House here to get a closer look at the panoramic views.
• After that, visit the Bryant Park, which is a well-maintained botanical garden that houses a variety of flowers and plants. You can also enjoy a picnic here or simply relax and soak in the beauty of nature.
• For lunch, head to one of the local restaurants and try some of the delicious South Indian cuisine, such as dosas, idlis, and vadas.
• In the afternoon, visit the Pillar Rocks, which are a set of three giant rock pillars that offer breathtaking views of the surrounding valleys. You can also take a short trek here to explore the area.
• Finally, end your day with a visit to the Bear Shola Falls, which is a beautiful waterfall surrounded by dense forests. You can take a dip in the cool waters or simply enjoy the scenic beauty of the falls.

I hope this itinerary helps you plan your day in Kodaikanal!