Latvia's official travel website lists a whopping nine things you can do or are expected to on Midsummer's eve.
These include wreath-making, decorating, leaping over the bonfire, looking for the mysterious fern flower and enjoying a friendly company until it's early in the morning. People will be seen dancing around maypoles as well, which is an ancient-seeming ritual if there is one.
Midsummer fairs are held across Latvia where you can stock up on precious midsummer flowers (alternatively, pick your own--there are plenty to choose).
Most people leave town on Līgo, but if you stay at the capital there'll be a lot of celebration on the river embankment replete with folk singers, dancers, Latvian actors, artists, bands and DJs.
The entertainment goes on into the wee hours and visitors can enjoy special foods and bonfires in the heart of the city. Riga-Pardaugava’s Dzegužkalns Park is another setting for the traditional all-night celebration.
Cases of overeating, DUI accidents, burns, drowning, and choking on food are reported each year, so please be careful.
Latvia's emergency services remind people to eat responsibly and drive when you're sober. Police will be conducting raids on Latvia's roads as each year.