One of the well-known examples of syncretism of Vishnu and Shiva is Ladu Baba or Ladukeswara in Nayagarh Hills. The little town of Saranakula is about 100 km from Bhubaneswar. The temple cluster was built in the 15th century AD.
The temple complex consists of a number of small and medium sized temples built in Odishan style. They are however decorated with a riot of colours. The prominent sculptures are the images of mother goddesses. An artificial pond is located beside the temple complex.
More pictures on the following link:
http://theideaofindia.in/ladu-baba-example-syncretic-cult-hari-hara/