Kolli Hills generally provides a secure environment for solo female travelers. Local people are usually warm and welcoming. You can also enjoy the peace and quiet with minimal incidents of harassment. However, due to its remote location and hilly terrain, it's advisable to be cautious when traveling, especially during night. Additionally, service providers like guides or accommodation staff are predominantly male, which might be a concern for some women. Thus, while it's generally safe, it's always smart and recommended to take appropriate preventative measures and stay alert to one's surroundings.