Lucas C.
Google
I started at the hervederos and hiked up, which i cannot recommend; the trail (which appears on maps.me) peters out in fields of corn, beans, sugar cane, and wild brush. So the feasibility of that route likely depends on the growing season. When i reached the crater, a man who said he was with the cooperative asked for 100 Córdobas to view the crater. This is separate from the payment at the entrance. Though he disappeared shortly thereafter, and missed the group that arrived after.
There are no facilities at the top--only a locked seismography station.
The day i arrived, Telica was very gassy, and i could not see much. On clear days, one can see lava in the crater. The crater is marvellous but somewhat unpleasant; it smells like sulfur and is covered in ash, so do not plan to picnic up there.
Check out the bat cave not far away and watch the sun set from the northern slope.