The Boulevard of Shards is the domain of The Trickster. He was originally trapped in it for the entirety of the first arc of PhantomVoices.
The dimension acts as a one-way door, thanks to a flaw in the Trickster's original design of it. Those who have enterred it have never escaped and very few accounts of it exist. Of the few descriptions of the Boulevard, it can be described as a completely empty street where day never comes. Signs can be seen pointing in a direction, only to lead inhabitants in circles. A mist surrounds the Boulevard and those who have attempted to navigate through the fog encounter the Trickster, only to never be seen again. Inhabitants have mentioned hearing echoes of familiar voices and seeing movement just out of their vision. Whether these are hallucinations brought on by insanity or jests played on them by the Trickster himself is unknown.
An interesting fact is that while time never moves in this domain, there are records of natural disasters and storms occuring in the Boulevard. There is proof that victims have died from these disasters, although the inhabitants claim to never find traces of other forms of life. There is currently no known way to enter the Boulevard.