Hi Richa! We did an evening/night Danube river cruise in Budapest during our visit to the city in the fall of 2017. I would personally recommend a night cruise which lasts about 1.5-2 hours (without dinner) to explore the major attractions like Buda Castle, Fisherman's Bastion, Hungarian Parliament, Chain Bridge etc in splendid lighting. The river cruises are guided and you will find a number of service providers, all offering similar prices and services, so you can choose as per itinerary and complimentary features. The cruises are available both on the Buda and Pest docks of the Danube, but the Pest side might offer more variety and options. We did it through the official Hop on Hop Off Budapest Tours as they are great value for money. You can also combine a hop on hop off bus tour of the city by road with the river cruise and get additional discounts on your river cruise tickets this way. While a normal cruise might cost you somewhere around 15-20 Euros per head, a cruise with drinks and/or dinner might stretch up to 35- 50 Euros depending upon what's on offer. You can check out various options and prices here: https://budapestrivercruise.com. Budapest at night through the river Danube is something that will stay with you a very long time.