There are many places on the Internet where you may find public domain pictures.
We have composed a list of these resources for your convenience.

Sep 15, 2013 - A Public Domain image is Free of charge. It is OK for personal or commercial usage and the creator does not need to be credited. Images selected for these boards are chosen for; good quality, color, contrast, sharpness and interesting subject matter. In most cases, the file sizes are large enough for printing.When downloading images, please read the licensing verbiage.

1. Jan 15, 2014 - Explore Judith Courtney's board 'Public domain', followed by 1612 people on Pinterest. See more ideas about public domain, stock photography free, stock images free.
2. Whether you’re a graphic designer, web developer, blogger or entrepreneur - we have lots of free public domain images that are perfect for your next project. Our free stock photo library features a mix of Creative Commons Images and Royalty-Free Images.

IMPORTANT. When you have found a beautiful picture for your new landscape, rember the link to the page. You will need to enter this link on submission to the Landscape Collection.

Search for pictures

1. Google.

• Open Advanced Image Search page
  
• At the bottom-right corner of the page you will find a choice box with 'not filtered by license' option selected.
  Change it to 'labeled for commercial use and modification'
  
• Enter the search keywords and click 'Search' button.

Example: Search for London (Labeled for commercial use and modification)

2. Flickr.

Google Images Public Domain

• Open Advanced Search page
  
• Scroll to the bottom and then check the following marks
  [x] Only search within Creative Commons-licensed content
  [x] Find content to use commercially
  [x] Find content to modify, adapt, or build upon
  
• Enter the search keywords and click 'Search' button.

Example: Search for Barcelona (Labeled for commercial use and modification)

Landscapes (Cities and Nature)

1. www.bigfoto.com
Navigate via the top-menu to a specific place of the world

Public Domain Images For Free

Example: Germany/Berlin

2. www.morguefile.com
Search for a place.
Example: Search for Paris

3. www.public-domain-image.com/architecture-public-domain-images-pictures
4. www.public-domain-photos.com/travel
5. www.public-domain-photos.com/landscapes
6. www.publicdomainpictures.net/browse-category.php?c=architecture&s=11

Landscapes (Nature only)

1. www.morguefile.com/archive/browse/#/?qury=landscapes&terms_all=landscapes
2. www.public-domain-image.com/nature-landscapes-public-domain-images-pictures
3. www.publicdomainpictures.net/browse-category.php?c=landscape&s=12

General public domain image collections

1. www.sxc.hu (gigantic archive, but registration required)

Public Domain Images.download The Best Public Domain Images Of

Collection of public domain image resources on Wikipedia
http://en.wikipedia.org/wiki/Wikipedia:Public_domain_image_resources