One of my favourite parts of Yerevan in the summer is the Children’s Railway. You can find it by going through the pedestrian tunnel which starts under Saryan street and gets to the Hrazdan gorge, turn left, walk through the small luna park, and down a long set of stairs.
The Children’s Railway was once one of many similar miniature-yet-fully-functioning railways which dotted cities across the former Soviet Union and Eastern Block. Sadly, it is now one of the few remaining such attractions.
The railway system includes 3 miniature train stations, each of which an architectural marvel in of itself. Tickets usually cost less than a dollar, while trains depart on the single 2km-long track every 15 or so minutes (depending on how full it is).
Though the railway is primarily intended for families with children, everyone is welcome. It’s just a unique thing to try while you’re visiting Armenia.
Afterwards, you can always picnic on the wooded slopes leading into the river.