From Shuushuu

Pixiv's memes spring from the many events located on the site. If you want to peruse the events, you should simply click the on the main page and you'll be transported to this page.

The page continues, but there's nothing more on it but a link to the top. The イベント管理 (your events) link will take you to a page with a section for events your circle has participated in (サークル参加するイベント) and one that you have participated in (一般参加するイベント).