Hopping off the bus from Ciudad del Este to Encarnación in Trinidad. Just let the driver know.
Next to the entrance there is the basic & clean "Hotel de las Ruinas". 150 000 Guaranis for a double room with bathroom & breakfast. The latter was very very poor: coffee & untoasted toast-bread.
Dinner for 25000G. Ok.
The ruins are nice & to be done in 1-2h.
From Trinidad/Hohenau or even Encarnacion, take a Pastoreo-Bus to Ynambu (2h) and visit the forest in San Rafael Park at PROCOSARA (www.procosara.org).
Spanish or German! Let them know in advance to be picked up in Ynambu.