The location of the grave marker of the prophet Joseph Smith, his wife Emma Smith and the prophets brother Hyrum Smith is in the Smith Family Cemetery in Nauvoo Illinois. The Smith Family Cemetery is a small plot of land adjacent the home of Joseph Smith. The Smith homestead is one of the homes closest to the entrance of the small town of Nauvoo. The homestead is very close to the Mississippi River and has a plot of land next to it now known as the Smith Family Cemetery, where the Joseph Smiths Family buried their loved ones. The Smith Family Cemetery is in between the Red Brick store(where the Relief Society was organized) and the Smith Family Homestead. Many of the Smith family homes and businesses are located very close to one another right around the cemetery.
In the Smith Family Cemetery you can see the grave markers of Joseph, Hyrum and Emma Smith, but this was not the first place the bodies of Joseph and Hyrum were buried. When they were first killed in Cathage Jail the bodies were buried near the shed in the back of the Smith Homestead. Their graves were not marked because of the bounty put on the Prophet Joseph Smiths head, from Missouri. Some time after the death of the prophet Joseph Smith, the Missouri River was dammed up and the water around the Smith Family Homestead was rising, worried that Joseph and Hyrums bodies would be swept away in the rising river, Joseph Smith III had the bodies exhumed and reburied. When digging for Joseph and Hyrums bodies, they ended up digging into Emma Smiths grave and buried the three, Joseph, Hyrum and Emma in a new location, higher on the plot of land.
Although, the Church of Jesus Christ of Latter-Day Saints does not own this home or the other homes of Joseph Smith Jr. you are still welcome to walk around the cemetery and around the grounds. The Community of Christ Church(formally known at the RLDS Church) owns the homes and properties of Joseph Smith, and are very welcoming to visitors and all who want to learn and honor the lives of the Prophet Joseph Smith, and his family.
If you are interested in touring the Smith family home, the Community of Christ does a very informative walking tour, they charge 5$ per person to tour the Smith Family homes. This tour is well worth the cost, they give a lot of pertinent information, the tour guides are educated and they know the majority of the people on the tour are Latter-Day Saints, and they are very respectful.