Kodachadri trek was something which was done several times by me with friends and once with wife. This is a hill closer to Kollur temple where it is supposed to have the roots (moola-sthan) of the actual Kollur temple. There are 2 temples here where both claim that they are the actual temples, but the one on the higher side seems to have a more priestly and divine feeling. One can come here in a Jeep hired from Kollur, as well as trek up for about 5-6 hours. This is a moderate trek mostly through vegetation and at times in open. Should be able to do by an average healthy person. Stay options are available in the houses next to the temples (house of priests) as well as there is a guest house. But not sure how to get permission to stay at the guest house. Still further there is Ganapati guha (cave), and Sarvagna peetam with a small temple for Adi Shankara which is at the pinaccle of the hill. Trek further down from there and you reach Chitramoola, a small cave where lot of sages are supposed to have meditated. I have stayed in this cave overnight 2 times, atop in Sarvagnapeetam once and once in the house of the priest