Vriddh Aditya temple is situated near, Varanasi Uttar Pradesh. This temple is known for its energetic and spirited vibes, as mentioned in Kashi Khand.

Legend
Vriddh Aditya a form of lord Surya is based on a true story. According to a story of an old man ‘Vriddhharit’ who was a brahmin used to live in Varanasi. He wanted to get young in order to practice ‘tapa’ (tapa is a practice carried out to attain spiritual power and purification, as being an old man, he was lacking strength which could be a hurdle in doing so.
So, he decided to establish an idol of Lord Surya on the southern side of Vishalakshi Devi and started praying to lord Surya. Being pleased with his prayers Lord Surya appeared before him and asked Vriddhharit to seek a boon, to which he replied that we wanted to be young to carry out the extreme practice of ‘tapas.
Lord Surya was impressed by his devotion and innocence and gave him a boon of ‘Soundaryrapunj Taran’ (youth) as wished by the Brahmin. Lord Surya established himself in a form of Vriddh Aditya in Varanasi. Since then, he is worshipped by his devotees.
As per beliefs, people who worship lord Surya in his form of Vriddh Aditya, devotees can attain siddhi and get relieved from all sorts of diseases.