Whether a cobblestone natural stone display rack should be placed outdoors or indoors depends on several factors, including the materials used in construction, the intended use, and the environmental conditions. Here are some considerations to help you decide:

1. **Material Durability:** If the display rack is constructed using materials that can withstand outdoor conditions, such as weather-resistant metals or treated wood, it may be suitable for outdoor placement. However, if the materials are susceptible to damage from exposure to sunlight, moisture, or temperature fluctuations, indoor placement may be preferable.

2. **Exposure to Elements:** Consider the level of exposure to outdoor elements such as rain, snow, wind, and sunlight. Outdoor placement exposes the display rack to these elements, which can cause deterioration, fading, or damage to the materials over time. Indoor placement provides protection from these environmental factors and may prolong the lifespan of the rack.

3. **Customer Access:** Think about customer access and visibility. Placing the display rack outdoors may attract more attention from passersby and potential customers, especially if it's located near a sidewalk or entrance. However, indoor placement allows for controlled access and may provide a more comfortable browsing experience for customers.

4. **Security:** Evaluate the security risks associated with outdoor placement, such as theft, vandalism, or damage from unauthorized handling. Indoor placement offers greater security and control over the display rack, reducing the risk of damage or loss.

5. **Maintenance Requirements:** Consider the maintenance requirements associated with outdoor placement, such as cleaning, repairs, and routine maintenance. Outdoor display racks may require more frequent maintenance to keep them clean and in good condition compared to indoor racks.

6. **Regulatory Considerations:** Check local regulations or building codes to ensure compliance with any restrictions or requirements for outdoor display racks. Some areas may have restrictions on outdoor advertising or display structures that need to be considered.

Ultimately, the decision to place a cobblestone natural stone display rack outdoors or indoors depends on your specific circumstances, preferences, and priorities. Evaluate the factors mentioned above to determine the most suitable location that meets your needs and objectives while ensuring the longevity and effectiveness of the display rack.