Heya
@Sinelius,
Thank you for the fantastic suggestion! We really liked this idea so it has already been implemented. The herbology classroom has been added under the Greenhouses, so that players know it's near there and there's also a short mention of it in the description. The potions classroom has received a whole new icon with a small description of how to get there.
Thank you very much for bringing this up to us. It's really appreciated, as it gave us a way to improve the server!
Take care and enjoy your day!