The 41-day 'Mandala pooja' season of the shrine will start tomorrow at the dawn of the month of 'Vrishchikam' of Malayalam calendar, followed by the 'Makaravilakku" phase lasting till mid-January next year.
One of world's largest religious events, Sabarimala attracts an average three crore devotees every year.
Various government departments, Travancore Devaswom Board and voluntary agencies are engaged in last-minute preparations to cope the inflow of devotees -- both at the Sannidhanam atop and the base camp on the banks of holy Pampa river.
Large contingents of police had been deployed to maintain security, crowd management and traffic control.
According to official sources, ensuring hassle-free darshan to pilgrims through effective crowd management and keeping the fragile ecosystem of the hill-shrine situated in the buffer zones of Periyar Tiger Reserves in Pathanamthitta district are some of the vital tasks.
The first phase of the pilgrimage will culminate with the 'mandala' pooja on December 26. It will be followed by the 'makaravilakku' with the 'jyothi darshan' as its highpoint on January 14.
Railways have announced Sabari special trains from different destinations like Chennai, Bangalore and Hyderabad.