There are several temples where Ravan is worshiped. Ravan is considered most revered devotee of Lord Shiva. The images of Ravan are seen associated with Lord Shiva at some places.

1. Ravan Mandir, Bisrakh, Greater Noida, Uttar Pradesh, India.

2. There is a huge Shivalinga in Kakinada, Andhra Pradesh, India. supposedly installed by Ravan himself, with a statue of Ravan near by. Both Shivalinga and Ravan are worshiped by the fishermen community there.

3. Thousands of Kanyakubja Brahmins of the village Ravangram of Netaran, in the Vidisha District of Madhya Pradesh, perform daily puja (worship) in the Ravan temple and offer naivedyam / bhog (a ritual of sacrifice to the Gods). Centuries ago King Shiv Shankar built a Ravan temple at Kanpur, Uttar Pradesh. The Ravan temple is opened once in a year, on Dashehra Day, to perform puja for the welfare of Ravan.

4. Ravan is said to have married Princess Mandodari at a place Mandsaur in Madhya Pradesh, India. This is so because in Mandsaur, Ravan is worshiped.

5. The Dave Brahmins of Mudgal Gotra, Jodhpur/Mandor who were originally from Gujarat, India claim to be the descendants of Ravan. The say that since time immemorial they are performing the shraddh (death anniversary) of Ravan on Dashehra Day every year. They offer pind daan and take a bath after that ritual. They recently erected a Ravan temple in Jodhpur, India where daily puja is performed.

source: https://en.wikipedia.org/wiki/Ravana