the Casa de Azotea contains a coffee museum, a small costume museum,and Casa Kojom, a music museum. (Kojom means music in some Maya languages.)
I especially liked the Music Museum. The woman working there not only explained the early instruments, she demonstrated most of them. A turtle shell struck with a deer antler makes a good rhythm instrument. Conch shells had beeswax around the hole to protect the mouth. Clay ocarinas and whistles are old instruments also. Marimbas are the national instrument of Guatemala. They were originally African, and came in with the slaves. Early ones had gourds as sound boxes.
The Coffee Museum has videos and dioramas to illustrate coffee growing and roasting, and there is some antique equipment to look at. The costume museum has some dioramas of daily life. Naturally, there is also a gift shop
Admission is $4 (30Q) and gets you into all of them. Hours: 8:30-4:30 M-F; 8:30-2 on Sat.
Directions: Go to Jocotenango Central Park and turn left. Entrance just past cemetery.
OR--Easier-- they run a shuttle that costs 5Q. It leaves from the Central Plaza in Antugua on the hour. Catch their minivan in front of the cathedral.
There isn't much outside Antigua, but if you want a feel for the local flavor of coffee and architecture venture out into Jocotenango. You may notice arches are common in government buildings. The coffe plantation is just outside Antigua. It is brewed fresh daily.