Using this create list in site level when the work flow activated in site level.
Step 1: Open VS with new empty SharePoint project in farm solution.

Step 2: Add a new item Sequential Workflow for site workflow.
Step 3: Choose Site workflow Option.

Step 4: Click Next And Finish.(Using site work flow we start manually by default).

Step 5: ClickOnworkflowActivity.

Step 6: Write Following Code.
  1. private void onWorkflowActivated1_Invoked(object sender, ExternalDataEventArgs e)
  2. {
  3. SPWeb topsite = workflowProperties.Web;
  4. topsite.Lists.Add("Hello", " ", SPListTemplateType.Contacts);
  5. SPList listcon = topsite.Lists["Hello"];
  6. listcon.OnQuickLaunch = true;
  7. listcon.Update();
  8. topsite.Update();
  9. }
After the deploy the project.Then go to site contents in our share point site.click site workflows and start that workflow and the output become create our list in that site.