If you're planning a day out in County Durham, this northernmost county in England offers a rich blend of history, natural beauty, and cultural attractions. Here are some delightful activities to consider:

1. Durham Cathedral and Durham Castle:
- Durham Cathedral, dating back to the 12th century, is a masterpiece of Romanesque and Gothic architecture. Marvel at its stunning design and explore the tombs of St. Cuthbert and the Venerable Bede. Don't miss the Chapel of the Nine Altars. While in Durham, visit Durham Castle, occupied by University College since 1840. Take a guided tour to explore its medieval great hall, Norman Chapel, and Tunstall Chapel with intricate carvings.

2. Barnard Castle:
- Despite its recent notoriety, Barnard Castle remains a top attraction in County Durham. Visit the Bowes Museum, home to the largest art collection in northern England. Explore the 12th-century Norman castle perched high on a rock overlooking the River Tees. Look for King Richard III's boar emblem carved into the castle wall.

3. North Pennines Area of Outstanding Natural Beauty (AONB) and High Force Waterfall:
- Discover the rugged beauty of the North Pennines AONB. Enjoy scenic walks, rolling hills, and breathtaking landscapes. Don't miss the High Force Waterfall, one of England's most impressive waterfalls.

4. Beamish Museum:
- Step back in time at the Beamish Museum, an open-air living museum near Stanley. Explore historic buildings, ride vintage trams, and immerse yourself in the past. It's a fascinating glimpse into the region's industrial heritage.

5. Raby Castle:
- Visit Raby Castle, a medieval fortress surrounded by beautiful gardens and deer parks. Explore its grand rooms, learn about its history, and enjoy the picturesque setting. Don't miss the views from the castle's towers.

Remember, County Durham offers a mix of cultural landmarks, natural wonders, and historic sites – perfect for an enriching and memorable day out!