You can find urban exploration groups by searching online on social media platforms like Facebook or Meetup. Look for groups that are specifically dedicated to urban exploration in your area. You can also reach out to local photography or adventure groups as they may have members who are interested in urban exploration. Additionally, attending local events or workshops related to urban exploration can help you connect with like-minded individuals who share your interest. **

Some popular urban exploration sites in Hamburg include the old Elbe Tunnel, which was built in 1911 and is now open to pedestrians and cyclists, offering a unique underground experience. The abandoned Flakturm IV in Wilhelmsburg is another intriguing site, featuring a massive World War II-era anti-aircraft tower that is now closed to the public but can still be admired from the outside. Additionally, the Bunker St. Pauli offers guided tours of a former air raid shelter that provides a glimpse into Hamburg's wartime history. These sites offer a fascinating look into Hamburg's past and are popular destinations for urban explorers. **

The difference between SPF 18 and SPF 8 is the level of sun protection they provide. SPF 18 offers higher protection against UVB rays compared to SPF 8. SPF 18 blocks about 94% of UVB rays, while SPF 8 blocks about 87% of UVB rays. Therefore, SPF 18 provides better protection and is recommended for those who spend more time outdoors or have fairer skin. **

Window glass SPF refers to the Sun Protection Factor of the glass used in windows. It measures the ability of the glass to block harmful UV rays from the sun. A higher SPF value indicates better protection from UV radiation, which can help reduce the risk of skin damage and fading of furniture and fabrics inside the building. It is important to consider window glass SPF when choosing windows for a building to ensure adequate protection from the sun's harmful rays. **

SPF 20 stands for Sun Protection Factor 20. It indicates that the sunscreen will provide 20 times the skin's natural protection against UVB rays, which are the main cause of sunburn and skin cancer. This means that if it takes 10 minutes for your skin to start burning without any protection, using a sunscreen with SPF 20 would theoretically allow you to stay in the sun for 200 minutes (10 minutes x 20). **

SPF 15 stands for Sun Protection Factor 15, which is a measure of how well a sunscreen will protect the skin from UVB rays. It indicates that the sunscreen will block approximately 93% of the sun's UVB rays, allowing only 1/15th of the rays to reach the skin. SPF 15 is considered to be a moderate level of protection and is suitable for everyday use for people with light to medium skin tones. It is important to reapply sunscreen every two hours, especially when swimming or sweating, to maintain its effectiveness. **

SPF 50 provides a high level of protection against the sun's harmful UVB rays. This level of protection helps to significantly reduce the risk of sunburn, skin damage, and skin cancer. It is especially important for individuals with fair skin, those who are prone to sunburn, and for use in intense sun exposure conditions. Overall, SPF 50 offers a strong defense against the sun's damaging effects on the skin. **

The Huawei P20 and P20 Lite are both solid smartphones with attractive designs and good camera capabilities. The P20, in particular, stands out with its Leica triple camera setup, providing excellent photo quality. The P20 Lite offers a more budget-friendly option with decent performance and features. Overall, both phones offer good value for their respective price points and are worth considering for those looking for a reliable smartphone with good camera capabilities. **