yes. it's one of the 8 sabbats, it's the opposite day of Yule, being the longest day of the year, the sun and Lord is at it's strongest, the Holly King is defeated by the Oak King, and summer begins, crops are planted/grown, the new born animals are reaching maturity, it's warm and sunny. typically, people get married around this time [or Yule] or rededicate themselves. [personally i do that on Beltane but whatever]
Midsummer or Litha isn't as widely celebrated as say Samhain or Yule, but it's one of the major holidays, and should be celebrated because it is the contrast of Yule where the Oak king [sun] is reborn, here on Midsummer, the opposite occurs, and the Oak king rules over the Holly King who shall be reborn and do battle once again to rule over the winder months again. it's a never ending cycle.