A nature study-cum-trekking expedition is being held by the Youth Hostels Association of India at Kambala Konda Eco Park on Saturday. Interested persons can contact the association's State secretary M. Krishna Murthy on mobile no. 94405 43989 or State treasurer A. Pundarikaksha on mobile no. 99492 32380 for further details and registration, according to YHAI State chairman Ch. Sreenivasa Prasad.