Reach vanayambadi from Chennai by taking the Chennai - Bangalore expressway.
Highway branches after Krishnagiri and you need to travel on highway going left to reach Vanayambadi. Do not be tempted to take the shortcut via Tirupatur as there is a stretch of mud road to navigate and 4 wheelers can get stuck there, plus you won't be saving much time.
'''The highway from Bangalore till Vanayambadi is a dream...''' You can cruise along at 120 kmph on 4 lane highway, some stretches of which are even better than US InterStates with 3 lanes + shoulder on each side separated by a wide median. The last 12 km from Vanyambadi - Yelagiri is lovely Ghat(mountain) Road which is wide enough and in good condition with very light traffic. If you travelling from Chennai to Yelagiri, the entire stretch is so good that you will be tempted to go over 120 kmph. Whenever, you pass through a town, need to watch out for pedestrians who cross the roads suddenly.
'''NB''':There are no petrol/gas stations in the hills, so you must fill up your tank before reaching the Ghat road. The last station that you can find is near the start of the hills after you take the turn from the national highway. You need to travel approximately 4 km to get that HP station. Except a few roadside repair shops that can only offer a tire change, there are no vehicle repair shops in the hills. There is a medical shop near Hotel Hills (in the beginning of the town). Nearest place where you have good medical facilities is Tiruppatur even though there is a primary health centre run by the Government in one of the villages catering to the basic needs of the people in villages.
There is also a lake where one can enjoy boating ( I would suggest being at lake by 9:00 - 9:30 am to avoid the rush after 10 am).
Next one can move 5 km down on main road to reach the valley view point at Swamy Malai. You will have to park the vehicle at temple on left side of road and '''trek uphill for an hour or so.''' A group of normal walkers (trekers?) would take one and a half hours uphill and one hour downhill. The trek is enjoyable passing through local farms with fruit trees near you (u can pluck a pomegranate or Shareefa/sitaphal to nibble upon). do not forget to carry water as there is no water up the hill. There is a small Siva temple that is constructed beneath a huge rock.
There is a water fall at the foothill for which u need to come down the hills reach the Jalagamparai waterfalls. Season to visit : June , July , August till Jan
Misty clouds
there is one TASMAC shop near the lake