Sand sculpture. The limestone boulders which lie in the bed of the Colorado River are carved and polished by the sand... by… https://www.rawpixel.com/image/14288702/photo-image-sand-animal-public-domainFree Image from public domain licenseSeveral examples of diseased placenta, numbered for key. Lithograph by Ridolfi after Ottavio Muzzi, c. 1843. https://www.rawpixel.com/image/13995063/image-paper-cartoon-artFree Image from public domain licenseBlue sky begins to break through the clouds over Arctic Ocean ice Sept. 9, 2009. Photo Credit: Patrick Kelley, U.S. Coast… https://www.rawpixel.com/image/4043205/photo-image-ocean-nature-mountainFree Image from public domain licenseAgriculture: a plough and other implements. Engraving by A. Bell. https://www.rawpixel.com/image/13970108/agriculture-plough-and-other-implements-engraving-bellFree Image from public domain licenseHorse and rider at show jumping competition, unknown location- 19 October 2015 https://www.rawpixel.com/image/6113193/photo-image-public-domain-person-freeFree Image from public domain licenseFive Pound Island, Gloucester Harbor. [Cape Ann, Mass.] by Proctor Brothers https://www.rawpixel.com/image/14298830/five-pound-island-gloucester-harbor-cape-ann-mass-proctor-brothersFree Image from public domain licenseFlock of birds flying in urban area in front of tall residential buildings with windows. Original public domain image from… https://www.rawpixel.com/image/3297363/free-photo-image-animal-apartment-building-birdFree Image from public domain licenseBurchell's Zebra and Foal. (Asinus Burchellii.) Foal born in Gardens 1865. Hab: Africa. by Frank Haes https://www.rawpixel.com/image/14291897/photo-image-person-animal-public-domainFree Image from public domain licenseLeyden Hills Sugaring operation, South Dakota by C W Johnson https://www.rawpixel.com/image/14293691/leyden-hills-sugaring-operation-south-dakota-johnsonFree Image from public domain licenseRuby-throated hummingbirdA female ruby-throated hummingbird visits a hummingbird feeder.Photo by Courtney Celley/USFWS.… https://www.rawpixel.com/image/4028525/photo-image-bird-summer-natureFree Image from public domain licenseThe dislocated thigh bone of a dog; and a fractured patella, numbered for key. Drawing. https://www.rawpixel.com/image/14002959/image-dog-paper-frameFree Image from public domain licenseFree close up dragonfly with white background image, public domain animal CC0 photo. https://www.rawpixel.com/image/5906973/photo-image-background-public-domain-natureFree Image from public domain licenseOesophagus, stomach and intestine from a case of poisoning by hydrochloric acid https://www.rawpixel.com/image/13964883/oesophagus-stomach-and-intestine-from-case-poisoning-hydrochloric-acidFree Image from public domain licensePressed tin firemark for Nordische Versicherunggs, Pohja Kinnitusselts in Estonia showing raised image of bear with company… https://www.rawpixel.com/image/9975573/image-art-fire-vintageFree Image from public domain licenseThe Hôtel de St. Paul and the Jesuit church in the Rue St. Antoine. Etching. https://www.rawpixel.com/image/13962373/the-hotel-st-paul-and-the-jesuit-church-the-rue-st-antoine-etchingFree Image from public domain licenseR.R. Station - Del Monte Hotel - Monteray [sic] by Carleton Watkins https://www.rawpixel.com/image/14309103/rr-station-del-monte-hotel-monteray-sic-carleton-watkinsFree Image from public domain licenseDropping Rocks below Alhambra, Trenton Falls, New York by John Robert Moore https://www.rawpixel.com/image/14293732/dropping-rocks-below-alhambra-trenton-falls-new-york-john-robert-mooreFree Image from public domain licenseCavalry Camp, Balaklava, looking towards the Plateau of Sebastopol. by Roger Fenton https://www.rawpixel.com/image/14284881/photo-image-horse-cow-personFree Image from public domain licenseCascade in Kauterskill Clove, Near Haines Fall. by Edward Anthony https://www.rawpixel.com/image/14286040/cascade-kauterskill-clove-near-haines-fall-edward-anthonyFree Image from public domain licenseSlapende hond en kat (1652 - 1659) by Karel du Jardin and Karel du Jardin https://www.rawpixel.com/image/13777500/slapende-hond-kat-1652-1659-karel-jardin-and-karel-jardinFree Image from public domain licenseGray FoxYou never know what might surprise you! This gray fox popped out of the woods only five feet from where we were… https://www.rawpixel.com/image/4028735/photo-image-woods-forest-summerFree Image from public domain licenseWheeler's New York Battery coming into Action, Battle of Gettysburg. U.S.A. [a painting] by John F Jarvis https://www.rawpixel.com/image/14291592/photo-image-horse-person-artFree Image from public domain licenseResting trumpeter swan, Yellowstone River by Neal Herbert. Original public domain image from Flickr https://www.rawpixel.com/image/4038359/photo-image-bird-waterFree Image from public domain licenseIndigo BuntingPhoto by Grayson Smith/USFWS. Original public domain image from Flickr https://www.rawpixel.com/image/4029152/photo-image-plant-bird-natureFree Image from public domain licenseFour women and two men swimming near bathing machines. Wood engraving. https://www.rawpixel.com/image/13971544/four-women-and-two-men-swimming-near-bathing-machines-wood-engravingFree Image from public domain licenseMeisjes miyamairi kimono met kraanvogels boven water (1920 - 1940) by anonymous https://www.rawpixel.com/image/13748462/meisjes-miyamairi-kimono-met-kraanvogels-boven-water-1920-1940-anonymousFree Image from public domain licenseWhite-fronted geesePhoto by Mike Budd/USFWS. Original public domain image from Flickr https://www.rawpixel.com/image/4028374/photo-image-bird-nature-2021Free Image from public domain licenseRed-headed woodpeckerPhoto by Mike Budd/USFWS. Original public domain image from Flickr https://www.rawpixel.com/image/4028351/photo-image-bird-nature-2021Free Image from public domain licenseBreve e sustantiale trattato intorno alle figure anathomiche delli più principali animali terestri, aquatili, et volatili /… https://www.rawpixel.com/image/14019649/image-paper-cartoon-artFree Image from public domain licenseBumle bee on goldenrodGoldenrod is a great late blooming plant that provides food for pollinators. We saw this bumble bee… https://www.rawpixel.com/image/4028794/photo-image-flower-plant-beeFree Image from public domain licenseSparky - the electric bison!Sparky is one tough bison! He overcame the odds and survived a lightning strike.Photo by Joanna… https://www.rawpixel.com/image/4029225/photo-image-nature-animalFree Image from public domain licenseA bear standing on the elevated shore of a stream is haranguing a swan and a bird below in the water. Etching by J. E.… https://www.rawpixel.com/image/13987628/image-cartoon-art-waterFree Image from public domain license