I would like to introduce one cool event that you can enjoy when you visit Prague.

Genre | Exhibition, Festival of light |
Recent Begins | 10 October 2019 |
Recent Ends | 13 October 2019 |
Frequency | Annual |
Location | Prague, Czech Republic |
Inaugurated | 2013 |
Website | http://www.signalfestival.com |
Signal Festival is a four-day festival of light art and emerging technologies in Prague, Czech Republic.
Held annually in October, lighting designers from the Czech Republic and abroad create lighting installations in streets and public spaces across the city, including famous historical landmarks.

SIGNAL has become the biggest cultural event in the Czech Republic in five years of its existence. Its unique integration of art, city space, and modern technology has drawn over 2 million attendees to Prague in overall. The festival brings visually attractive works together with complex installations of international quality. Its concept allows it to appeal both to professionals and general public.
With its support of new works of art, the SIGNAL Festival has become a respected platform on an international scale and a sought-after venue for introducing the newest projects of the field. The financing of the festival is drawn from the support of grant programs such as those of the Magistrate of the Capital City of Prague, the Ministry of Regional Development, and the municipal districts involved, as well as through partnership with commercial entities and revenues from the auxiliary activities of the festival.
*From my real experience in 2016, people at the time are not that many as expected compared to other international events in Europe. (Well, maybe just because I expected super mega impossible number of people)
For upcoming festival in 2020, it will be 15-18/10 2020,so if you want to plan to experience this splendid view on your own eyes, check out official website to get information in details.
