Businesses involved in the preservation of historical sites help protect places of archaeological, architectural or cultural importance and retain their historic character. Sites may include monuments, ruins, historic buildings, gardens, industrial remains and areas containing archaeological evidence. Services often begin with research, measured surveys and assessments of a site's condition, significance and risks. Specialists may prepare conservation plans and advise owners or site managers on suitable long-term care. Practical work can include stabilising structures, repairing historic materials, controlling damp and water run-off, managing vegetation, and protecting archaeological remains from erosion or disturbance. Projects may also involve monitoring, recording and maintenance, with repairs designed to be compatible with the original fabric and to avoid unnecessary alteration.