Transcendence Directory is a project offering curated listings across a wide range of Western esotericism, practices, traditions, modalities, and research.
Gaelic Matters is a website that talks about Gaelic Scotland and Ireland, including information on the languages, symbols, religion, festivals, customs, traditions, sports, music, food and more.
An entire section of the website is dedicated to the Celtic religion. Though it can be challenging to get a real understanding of Celtic religion anywhere in Europe because there is little recorded, Christian monks did write down many of the ancient Celtic tales and Celtic traditions, which helps scholars to understand religious practice in early Gaelic Ireland.
Some of the beliefs and practices covered on the website include: the polytheistic nature of the religion, the practice of animal and human sacrifice, the different communal and ritual celebrations, supernatural beings, immortality, the belief that the world was alive, and the four main dates of Celtic festivals.