The Asopos river, originating from Kithairona, flows approximately fifty-seven kilometers before reaching Oropos, near the community of Chalkoutsiou. The environmental impact of the river's waters has been a topic of concern in the media for years, with plenty of information available online from various sources. The area near the river resembles a former dump site, with flood debris, garbage, and unknown materials partially buried in the sand. Despite this, some shore anglers continue to fish along the riverbanks. The pollution eventually reaches the southern Euboean Gulf, a popular destination for vacationers, fishermen, and boaters each year.